Apparatus for providing a connection to a wide area network for voice calls, a power management circuit, and a method for providing a connection to a wide area network for voice calls

ABSTRACT

An apparatus for providing a connection to a wide area network for voice calls includes a wide area network circuit configured to transmit voice call data packets, a phone connection circuit configured to receive a voice call signal from a phone, a processor circuit configured to generate voice call data packets based on a voice call signal received by the phone connection circuit and a power management circuit configured to switch off at least a part of the apparatus to reach a power down mode of the apparatus, if a supply voltage drops below a supply voltage threshold.

FIELD

Examples relate to concepts for emergency power supply of communicationdevices and in particular to an apparatus for providing a connection toa wide area network for voice calls, a power management circuit and amethod for providing a connection to a wide area network for voicecalls.

BACKGROUND

Traditional phone systems require little power to operate. In the past,telephone power was provided and guaranteed by the Central Office (CO).In case of loss of power, such as a power failure during an emergency,the phone would continue to work because it was powered through the CO,as was the case for POTS (Plain Old Telephone Service) and ISDN(Integrated Services Digital Network) services.

With telecommunication becoming more and more digital, the customerpremise equipment (CPE) cannot be efficiently powered any longer fromthe CO as power consumption is too high. Nevertheless, it is stilldesired to enable an emergency call in case of loss of power.

BRIEF DESCRIPTION OF THE FIGURES

Some examples of apparatuses and/or methods will be described in thefollowing by way of example only, and with reference to the accompanyingfigures, in which

FIG. 1 shows a schematic overview of an apparatus for providing aconnection to a wide area network for voice calls;

FIG. 2 shows a schematic example of an emergency power management unitintegrated into customer premise equipment;

FIG. 3 shows a schematic block diagram of a power management circuit;

FIG. 4 shows an example of a power management circuit; and

FIG. 5 shows a flowchart of a method for providing a connection to awide area network for voice calls

DETAILED DESCRIPTION

Various examples will now be described more fully with reference to theaccompanying drawings in which some examples are illustrated. In thefigures, the thicknesses of lines, layers and/or regions may beexaggerated for clarity.

Accordingly, while further examples are capable of various modificationsand alternative forms, some particular examples thereof are shown in thefigures and will subsequently be described in detail. However, thisdetailed description does not limit further examples to the particularforms described. Further examples may cover all modifications,equivalents, and alternatives falling within the scope of thedisclosure. Like numbers refer to like or similar elements throughoutthe description of the figures, which may be implemented identically orin modified form when compared to one another while providing for thesame or a similar functionality.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, the elements may bedirectly connected or coupled or via one or more intervening elements.If two elements A and B are combined using an “or”, this is to beunderstood to disclose all possible combinations, i.e. only A, only B aswell as A and B. An alternative wording for the same combinations is “atleast one of A and B”. The same applies for combinations of more than 2Elements.

The terminology used herein for the purpose of describing particularexamples is not intended to be limiting for further examples. Whenever asingular form such as “a,” “an” and “the” is used and using only asingle element is neither explicitly or implicitly defined as beingmandatory, further examples may also use plural elements to implementthe same functionality. Likewise, when a functionality is subsequentlydescribed as being implemented using multiple elements, further examplesmay implement the same functionality using a single element orprocessing entity. It will be further understood that the terms“comprises,” “comprising,” “includes” and/or “including,” when used,specify the presence of the stated features, integers, steps,operations, processes, acts, elements and/or components, but do notpreclude the presence or addition of one or more other features,integers, steps, operations, processes, acts, elements, componentsand/or any group thereof.

Unless otherwise defined, all terms (including technical and scientificterms) are used herein in their ordinary meaning of the art to which theexamples belong.

FIG. 1 shows a schematic overview of an apparatus 100 for providing aconnection to a wide area network for voice calls. The apparatuscomprises a wide area network (WAN) circuit 110 configured to transmitvoice call data packets 112 (e.g. to a communication network or acentral office). Further, the apparatus 100 comprises a phone connectioncircuit 120 configured to receive a voice call signal 122 (e.g. from aphone) and a processor circuit 130 configured to generate voice calldata packets 112 based on a voice call signal 122 received by the phoneconnection circuit 120. Additionally, the apparatus 100 comprises apower management circuit 140 configured to trigger switching off atleast a part of the apparatus 100 to reach a power down mode of theapparatus 100, if a supply voltage 150 drops below a supply voltagethreshold.

By switching off at least a part of the apparatus to reach a power downmode if a supply voltage drops below a supply voltage threshold, thepower consumption of the apparatus may be significantly reduced. In thisway, less battery power may be needed to enable basic functions (e.g.emergency calls) of the apparatus.

The apparatus 100 may be Customer Premise Equipment (CPE), a residentialgateway, a home gateway, a voice over Internet Protocol (IP) device,and/or a voice over Long-Term Evolution (LTE) device for providing aconnection to a wide area network for voice calls.

The wide area network (WAN) circuit 110 may be a circuit configured totransmit voice call data packets 112, such as, for example, a digitalsubscriber line (DSL) transceiver, cable modem transceiver, passiveoptical network (PON) transceiver, or wireless transceiver. The widearea network WAN circuit 110 may be a transceiver circuit configured toreceive data to be transmitted from the processor circuit. The voicecall data packets 112 may be data packets of a voice over IP call.

The phone connection circuit 120 may be a circuit configured to receivea voice call signal 122 from a phone (e.g. an analog phone or digitalenhanced cordless telecommunications (DECT) phone), such as, forexample, a foreign exchange station (FXS) circuit or a DECT circuit. Thevoice call signal 122 may be an analog phone signal or a digital phonesignal.

The processor circuit 130 may be a circuit configured to generate voicecall data packets 112 based on a voice call signal 122 received by thephone connection circuit 120, such as, for example, a networkmicroprocessor and/or a system on chip SoC processor. Voice call datapackets may also include the packets to establish and end a voice call,not just voice (speech) data.

The power management circuit 140 may be configured to switch off atleast a part of the apparatus to reach a power down mode of theapparatus, if a supply voltage 150 drops below a supply voltagethreshold. As long as the supply voltage 150 is above the supply voltagethreshold, the apparatus may provide full functionality. If the supplyvoltage 150 drops below a supply voltage threshold (such as during apower outage), then the power management circuit 140 may triggerswitching off at least a part of the apparatus to enter a power downmode in order to minimize power consumption. For example, during thepower down mode (or emergency standby mode), the power managementcircuit 140 may disable power from an emergency supply (e.g. battery) toa part or the complete WAN circuit 110 and/or a part or the completeprocessor circuit 130. The power management circuit 140 may trigger theswitching off at least a part of the apparatus by providing one or moreswitch control signals (e.g. gate signals of transistors) controllingone or more switches which control the flow of current to a part or thecomplete WAN circuit 110 and/or a part or the complete processor circuit130. Alternatively or additionally, the power management circuit 140 mayprovide one or more power control signals to one or more parts of theapparatus 100 (e.g. the WAN circuit 110 and/or the processor circuit130) to trigger the one or more parts of the apparatus 100 to switch offone or more parts of the apparatus 100.

During normal operation, the supply voltage may be provided externallythrough a supply voltage connection of the apparatus 100 from the powergrid, for example. If the external power supply drops below a supplyvoltage threshold (e.g. during a power outage), the apparatus 100 maychange into the power down mode. The supply voltage threshold may bebelow a nominal power supply voltage of the apparatus (e.g. 80% of anominal power supply voltage).

The power down mode may be a mode of the apparatus 100 with reducedfunctionality. In the power down mode, the remaining functionalities ofthe apparatus 100 may be powered by a battery. The apparatus 100 mayhouse the battery or the battery may be connectable to the apparatus100. For example, the apparatus 100 may still enable emergency calls inthe power down mode.

The power management circuit may comprise a voltage detection circuitconfigured to detect when the supply voltage drops below the supplyvoltage threshold. Alternatively, the power management circuit 140 mayrely on an external meter or monitor to detect when the supply voltage150 has dropped below the supply voltage threshold. In other words, thepower management circuit 140 may monitor the supply voltage 150.

During a power outage or other emergency, there may be a demand formaking a phone call. The power management circuit may be configured totrigger switching on an emergency part of the apparatus to change to anemergency call mode of the apparatus, if an emergency call demand isdetected. The emergency call demand may be detected by monitoring one ormore signals of the various circuit components of the apparatus 100. Anemergency call may be any call desired in the power down mode of theapparatus 100. The emergency call may be a call to an emergency numberor any other call necessary during a power outage or during a timenormal power supply of the apparatus 100 is not possible.

The power management circuit may comprise a current detection circuitconfigured to detect the emergency call demand, if a current is higherthan a current threshold. For example, in the power down mode, the powermanagement circuit may retain a connection to the phone connectioncircuit. The power management circuit may monitor the phone connectioncircuit for a signal that may indicate a demand for an emergency call.When the phone is picked up, the power management circuit may detect achange in current (beyond a current threshold) to the phone connectioncircuit, indicating an emergency call demand.

Once an emergency call demand is detected, the power management circuitmay trigger switching on an emergency part of the apparatus to enable anemergency call mode. This may be accomplished by directly controllingthe switches which control the flow of current to various systemcomponents (e.g. by controlling power to the emergency parts of theapparatus directly). Alternatively or additionally, this may also beaccomplished by issuing a signal (e.g. a boot mode emergency mode ornormal operation mode signal) while enabling power to the processor, aSoC, and/or other system controller. By issuing a signal such as a bootmode signal, the processor, SoC, and/or other system controller may onlyboot or enable the appropriate parts of the apparatus 100. For example,if an emergency mode boot signal is given, the system controller (e.g.the processor circuit) may only enable the emergency parts of theapparatus.

The power management circuit 140 may be configured to trigger keeping anon-emergency part of the apparatus switched off in the emergency callmode. In order to minimize energy consumption, the power managementcircuit may only boot the emergency parts of the apparatus in theemergency call mode as described above. Thus, any non-essential (e.g.non-emergency) parts of the system may remain in the power down mode.This may be accomplished in a manner analogous to enabling the emergencyparts of the apparatus: by directly controlling power flow to thevarious components via the power management circuit itself, or, byissuing an appropriate boot mode signal to the processor or systemcontroller as explained above. In this way, non-emergency parts of thesystem remain powered down and power consumption may be reduced orminimized.

The apparatus 100 may further comprise at least one of a LAN circuit(e.g. Ethernet circuit and/or WiFi circuit) and data bus circuitry (e.g.Universal Serial Bus USB and/or Serial AT Attachment SATA), which may bepart of the non-emergency part of the apparatus. The LAN circuit and/orthe data bus circuitry may be switched off in the power down mode and inthe emergency call mode of the apparatus 100.

The wide area network circuit 110 may be part of the emergency part ofthe apparatus. Similarly, the phone connection circuit 120 may comprisea foreign exchange station circuit, wherein the foreign exchange stationcircuit may be part of the emergency part of the apparatus. For example,when the system is in emergency call mode, the phone connection circuitmay be enabled to receive the voice call signal, the WAN circuit may beenabled to transmit the voice call data packets, and the processorcircuit may be enabled to convert the phone call signal to voice calldata packets.

The processor circuit 130 may be a network microprocessor implemented assystem on chip. By implementing the processor circuit as a system onchip, several other components may be implemented on the samesemiconductor die. For example, the wide area network WAN circuit 110,the phone connection circuit 120 and/or the power management circuit 140may be implemented on the same semiconductor die as the processorcircuit 130.

The power management circuit 140 may be configured to switch off thesystem on chip completely in the power down mode. The power managementcircuit 140 may control power to the processor circuit or system on chipin order to enter power down mode. Alternatively, the power managementcircuit 140 may issue a standby (or boot down) command to the processorcircuit or system on chip in order to enter standby (or a low powermode) in the power down mode.

The power management circuit 140 may be configured to trigger switchingon an emergency part of the system on chip in the emergency call mode,while a non-emergency part of the system on chip may be kept switchedoff. The emergency part of the system on chip may be required forenabling an emergency call. The power management circuit may triggerswitching on only the emergency part of the system by issuing a bootmode or similar signal as discussed above. For example, the powermanagement circuit 140 may provide power (e.g. from a battery) and anemergency mode signal to the processor circuit 130 in order to get intothe emergency call mode of the apparatus 100. For example, if the powermanagement circuit 140 sends an emergency mode signal to the processorcircuit while enabling power to it, then the processor circuit 130 mayonly enable the emergency parts of the system while the non-emergencyparts may be kept switched off.

The apparatus may further comprise a battery. The power managementcircuit may be powered by the battery in the power down mode. Forexample, the power management circuit 140 switches to power down modewhen the supply voltage has dropped below the supply voltage threshold(e.g. during a power outage) and in order to enable emergency call mode,an alternate source of power is needed. Thus, the power managementcircuit may switch to being powered by a (rechargeable) battery,generator, or alternative power source while in the power down mode inorder to be able to function and enable emergency calling mode.

By enabling power down mode and disabling non-emergency parts of theapparatus, substantial power savings can be achieved. For example, thebattery may have an energy capacity of less than 3 Wh (or less than 1 Whor less than 0.3 Wh). Such a battery may enable to supply standby timesof 24 hours and active talk times of 10 minutes. The power managementcircuit 140 may be configured to connect the battery to the phoneconnection circuit in the power down mode to enable the detection of anemergency call.

When the supply voltage drops below the threshold, the power managementcircuit 140 may be no longer able to supply the whole apparatus with theneeded power and switches to power down mode. The power managementcircuit may be configured to disconnect the battery from the processorcircuit in the power down mode. In this way, the power managementcircuit may provide necessary power to monitor the phone connectioncircuit for an emergency call demand (e.g. by monitoring changes in thecurrent corresponding to a phone being taken off the hook), whilesimultaneously disabling power to other system components. Until anemergency call demand is detected, there may be no need for theremaining circuits to be active. Both at least a part of the emergencyand the non-emergency parts of the system may be powered down until theemergency call demand is detected.

Once an emergency call demand is detected, the power management circuitmay enable the emergency parts of the apparatus (e.g. those componentsneeded to make the emergency call). The power management circuit 140 maybe configured to connect the battery to the processor circuit in theemergency call mode. In this way, the power management circuit 140 mayprovide power to the processor circuit 130 (and/or other system on chipand/or system controller) so that the processor circuit can enable theemergency parts of the apparatus (e.g. to receive the voice call signalsfrom the phone connection circuit and process them into voice datapackets to be sent by the WAN circuit).

For example, if the supply voltage returns above the supply voltagethreshold (e.g. the power outage has ended), then the system does notneed to operate in power down or emergency call mode any longer. Thepower management circuit 140 may be configured to disconnect the batteryfrom the wide area network circuit and the processor circuit, if thesupply voltage is above the supply voltage threshold. The powermanagement circuit 140 may also be configured to disconnect the batteryfrom the phone connection circuit or any other emergency parts of theapparatus if the supply voltage is above the supply voltage threshold.The power management circuit 140 may also be configured to connect thebattery to the charging circuit.

The wide area network WAN circuit 110, the phone connection circuit 120,the processor circuit 130 and/or the power management circuit 140 may beindependent hardware units are may be implemented at least partlytogether. For example, at least a part of the wide area network WANcircuit 110, at least a part of the phone connection circuit 120, atleast a part of the processor circuit 130 and/or at least a part of thepower management circuit 140 may be implemented as a system-on-chipdevice.

FIG. 2 shows a schematic example of an apparatus 200 with an emergencypower management unit integrated into customer premise equipment. Theimplementation of the apparatus 200 may be similar to the implementationof the apparatus 100 described in connection with FIG. 1. The apparatus200 comprises a CPE 201 (e.g. a gateway). The CPE 201 comprises a WANcircuit 110, phone connection circuit 120 (comprised of foreign exchangestation FXS circuit), a processor circuit 130 (implemented as aSystem-on-Chip (SoC)), a power management circuit 140, a DCin powersupply 150, a charging circuit 152, and a battery 154. The apparatus 200may further comprise data bus circuitry and/or LAN circuitry.

The WAN circuit 110, the phone connection circuit 120, the data buscircuitry, and/or the LAN circuitry may be implemented within the systemon chip, as discrete units within the CPE 201, or as separate discretedevices connected to the CPE 201 by means of the various systeminterfaces (i/f) in the processor circuit 130 (e.g. WAN i/f, Data i/f,and/or LAN i/f).

The DCin supply voltage 150 provides power via power supply input A tothe power management circuit 140 and to the charger station 152. Inturn, the charger station 152 charges the rechargeable battery 154,ensuring that the battery is charged should a power outage occur. Shouldthe DCin supply voltage 150 drop below the supply voltage threshold, thebattery 154 may be able to provide power via power supply input B to thepower management circuit 140.

The phone connection circuit (FXS) 120 is connected to an externalanalog phone 121. The phone connection circuit 120 is connected to powermanagement circuit 140 through power supply output D.

The processor circuit 130 may be configured to receive voice callsignals 122 from the phone connection circuit 120. The processor circuit130 may process the voice call signals 122 received from the phoneconnection circuit 120 via analog phone 121. The processor circuit 130may also comprises a WAN circuit 110 configured to transmit the voicecall data packets 112 to a central office 111 by means of a WANconnection. The processor circuit 130 may be connected to the powermanagement circuit 140 by means of power supply output C. In addition, aboot mode signal may be provided to the processor circuit 130 by thepower management circuit 140 by means of signal E (e.g. via an inputpin).

FIG. 2 shows a possible integration of an emergency power managementunit which may reduce the required battery capacity by a factor of 100or more. This can lead to a cost reduction and/or increase inreliability.

The emergency power management unit may assure minimum power consumptionin emergency mode, e.g. when main power supply, and therefore DCin, isoff. Further, a minimized battery capacity may be sufficient toguarantee required standby and emergency call durations, e.g. 24 hoursstandby and 10 minutes emergency call. The circuitry (e.g. NetworkuP+Peripherals, SoC) may be completely powered off in an emergency mode.A fast “wake-up” of uP and required peripheral may be performed when aphone gets off-hook in emergency mode. For example, the customer may geta dial tone within max. 200 ms (or 500 ms or 1000 ms).

More details and aspects are mentioned in connection with the examplesdescribed above or below. The example shown in FIG. 2 may comprise oneor more optional additional features corresponding to one or moreaspects mentioned in connection with the proposed concept or one or moreexamples described above (e.g. FIG. 1) or below (e.g. FIGS. 3-5).

FIG. 3 shows a schematic block diagram of a power management circuit300.

The power management circuit 300 comprises at least one switch 310 and aswitch control unit 320 configured to control the at least one switch310. The power management circuit 300 further comprises a batterycontact interface 330 for connecting the power management circuit 300 toa battery (or other power source). The power management circuit 300further comprises a phone contact interface 340 for connecting the powermanagement circuit 300 to a phone connection circuit. Additionally, thepower management circuit 300 comprises a processor contact interface 350for connecting the power management circuit 300 to a processor circuit.The contact interfaces may be interfaces for establishing an electricalconnection to an external circuit (e.g. solder contact points or a plug)or they may be direct electrical connections between the respectivecomponents and the power management circuit 300 (e.g. if the powermanagement circuit 300 is integrated into the same package as the othercircuitry).

The switch control unit 320 is configured to control the at least oneswitch 310 to electrically connect the processor contact interface 350to the battery contact interface if a current through the phone contactinterface increases beyond a current threshold. The power managementcircuit 300 may trigger powering on system components that are otherwisepowered down (e.g. the processor circuit) once an emergency call demandis detected. This may be accomplished by controlling the flow of currentto the various contact interfaces via the at least one switch 310 bymeans of the switch control unit 320.

The power management circuit 300 may disconnect power from the processorcircuit or other peripherals (through the respective contact interfaces)in order to minimize power consumption. While power is disconnected, thepower management circuit 300 may monitor the current flow to the phoneconnection circuit through the phone contact interface 340. A change incurrent beyond a current threshold may be a signal that an emergencycall demand is desired. In response, the switch control unit 320 maycontrol the at least one switch 310 so as to establish a flow of currentto the processor circuit by means of the processor contact interface350. The system may be kept in a power down mode until an emergency calldemand is detected, at which time power may be supplied to an externalprocessor circuit in order to enable an emergency call. The processorcircuit may then enable power to any other necessary emergencycomponents (such as a WAN circuit).

The power management circuit may further comprise a WAN contactinterface for connecting the power management circuit to a WAN circuit.The switch control unit may be configured to control the at least oneswitch to connect the WAN contact interface to the battery contactinterface if the current through the phone contact interface increasesbeyond a current threshold. In other words, the power management circuitmay be able to power the WAN circuit directly.

In some examples, the battery may further comprise a charging contactinterface for connecting the battery to a charging circuit.

More details and aspects are mentioned in connection with the examplesdescribed above or below. The example shown in FIG. 3 may comprise oneor more optional additional features corresponding to one or moreaspects mentioned in connection with the proposed concept or one or moreexamples described above (e.g. FIG. 1-2) or below (e.g. FIGS. 4-5).

FIG. 4 shows a schematic example of a power management circuit 400according to an example. The implementation of the power managementcircuit 400 may be similar to the implementation of the power managementcircuit 130 described in connection with FIGS. 1-2 or the powermanagement circuit 300 described in connection with FIG. 3. FIG. 4 showsa more detailed schematic of an emergency power management unit EPMUwith 4 supply ports A, B, C, and D, where A and B are inputs, C and Dare outputs and a fifth signaling port E indicating the operational mode(e.g. normal operation or emergency mode). It includes 4 switches 410which are controlled by a switch control unit 420. The number ofswitches might vary in different implementations.

The power management circuit 400 comprises switches 410 (individuallylabeled as switches 1, 2, 3, and 4) and switch control unit 420configured to control the switches 410. The power management circuit 400further comprises a DCin contact interface A for connecting powermanagement circuit 400 to a supply voltage, a battery contact interfaceB for connecting the power management circuit 400 to a battery, aprocessor contact interface C for connecting the power managementcircuit 400 to a processor circuit, and a phone contact interface D forconnecting the power management circuit 400 to a phone connectioncircuit. The power management circuit 400 may further comprise an outputsignal E for providing a boot mode signal (or an un-boot or boot downsignal) to the processor circuit. The power management circuit has twopower supply in lines (A and B) and two power supply out lines (C andD).

The power management circuit 400 may also comprise a voltage sensor 422(e.g. a voltmeter or voltage tester) and/or a current sensor 424 (e.g. aresistor). The voltage sensor 422 may monitor the incoming supplyvoltage from input A. When the supply voltage is greater than a supplyvoltage threshold (e.g. V>V_(limit)), the power management circuit 400is in normal operation mode (e.g. the gateway is operated from the mainpower supply). When the supply voltage is below a supply voltagethreshold (e.g. V<V_(limit)), the power management circuit 400 entersthe emergency operation mode (e.g. gateway is operated from battery andonly allows outgoing emergency calls). In the emergency operation mode,the current sensor 424 gets into operation.

In other words, if the supply voltage drops below the supply voltagethreshold, then the power management circuit 400 switches from normaloperation to Emergency Stand-by mode by disabling the power connectionsfrom the supply in (switch 1) and processor circuit (switch 3), whileenabling power connections from the battery (switch 2) and to the phoneconnection circuit (switch 4). Simultaneously, the current detector 424is activated, monitoring the phone connection interface for an emergencycall demand. In this way, the system switches from normal operation toan emergency stand-by mode where the analog phone is monitored for achange in current (e.g. an emergency call demand). Prior to disablingthe connection to the processor circuit, the boot-mode signal may beused to power down the processor circuit and/or other circuit components(e.g. related or unused signals) in a controlled manner. For example,rather than simply cutting power to the processor circuit (which maylead to memory damage or a malfunction on reboot), the power managementcircuit may issue a boot down command to the processor circuit.

This is summarized in the table below. The switch control unit 420controls the switches 410, for example, according to the table below,where V and I represent the reading of the voltage sensor 422 andcurrent sensor 424, respectively.

State Switch 1 Switch 2 Switch 3 Switch 4 State Name V > Vlimit I =don't care 11 ON OFF ON OFF Normal Operation 10 V < Vlimit I < Ilimit 00OFF ON OFF ON Emergency Stand-By I > Ilimit 01 OFF ON ON ON EmergencyActive

In state ‘00’ the network processor and its peripherals are not powered(switch 3 is OFF), but the phone connection circuit (FXS) remainspowered through the battery (switches 2 and 4 are ON). In state ‘01’ theswitch control unit 420 detects, for example, a so-called Off-Hook stateby detecting a current that is higher than a specified limit. If thenetwork processor gets powered into the “Emergency Active” mode, it candetect by port E, that only a very limited emergency mode operation isrequired, where only communication between FXS and WAN port issupported. Therefore only a limited feature set may be enabled andboot-up can be made very quickly, e.g. execution out of flash.

In other words, under normal operation, the system is in state ‘11’ withswitches 1 and 3 ON and switches 2 and 4 OFF. In normal operation mode,power is provided to the various circuitry through the power managementcircuit by means of the DCin supply voltage. In the example shown in thetable above, the battery and phone connection circuit may bedisconnected (e.g. their respective switches, 2 and 4, are turned OFF)while in normal operation mode. In other examples, the phone connectionand FXS circuitry may continue operating in normal operation mode (e.g.switch 4 may remain ON in state ‘11’). In some examples, the currentdetection sensor 424 may be integrated in the phone connection circuitand/or FXS.

Should the DCin supply voltage drop (V<V_(limit)), then the systemswitches to an “Emergency Stand-by” mode. In this mode, the powermanagement circuit 400 turns switch 3 OFF to disable power to theprocessor circuit and other peripherals, conserving power.Simultaneously, the power management circuit turns switches 2 and 4 ON,enabling battery power to the phone connection circuit (and to anexternal analog phone). The power management circuit 400 monitorscurrent detector 424 for a change in the current beyond the currentthreshold.

If there is no change in the current I (e.g. I<I_(limit)) then thesystem remains in the power down mode conserving power. An emergencycall demand is detected once a change in the current is detected (e.g.I>I_(limit), for example corresponding to a phone being picked up offthe hook). Once the emergency call demand is detected, the powermanagement circuit 400 switches to “Emergency Active” mode. In thismode, switch control unit 420 turns switch 3 ON, enabling power to theprocessor circuit. The switch control unit 420 may also send a boot modesignal via port E to the processor circuit so that the processor circuitboots only the emergency parts of the system (e.g. those parts needed tocomplete the call, such as the phone connection circuit, the WANcircuit, and the processor circuit) while keeping non-emergency parts ofthe system off (such as data bus circuitry or LAN circuitry). Thus, theemergency parts of the system are only turned on when an emergency calldemand is detected. The rest of the time the system is in power downmode (emergency stand-by mode) and system power is conserved.

More details and aspects are mentioned in connection with the examplesdescribed above or below. The example shown in FIG. 4 may comprise oneor more optional additional features corresponding to one or moreaspects mentioned in connection with the proposed concept or one or moreexamples described above (e.g. FIG. 1-3) or below (e.g. FIG. 5).

FIG. 5 shows a flowchart of a method 500 for providing a connection to awide area network for voice calls.

The method 500 may comprise 510 receiving a voice call signal from aphone by a phone connection circuit. The method 500 may further comprise520 generating voice call data packets by a processor circuit based onthe voice call signal received by the phone connection circuit. Themethod 500 may further comprise 530 transmitting voice call data packetsby a wide area network circuit based on the voice call data packetsgenerated by the processor circuit. Additionally, the method 500 maycomprise 540 switching off at least one of the processor circuit and theWAN circuit, if a supply voltage drops below a supply voltage threshold.Thus, if an input supply voltage drops below a supply voltage threshold(e.g. during a power outage), the processor circuit and/or the WANcircuit may be powered down to conserve any remaining sources of power.

The method 500 may further comprise triggering switching on at least apart of the processor circuit and WAN circuit to change to an emergencycall mode if an emergency call demand is detected. In other words, ifthe supply voltage drops below the supply voltage threshold and thecircuits are powered down, the system may monitor for a change ofcurrent corresponding to an emergency call demand. Once an emergencycall demand is detected, the emergency parts of the system (e.g. theprocessor circuit and WAN circuit necessary to complete an outgoingcall) may be powered on temporarily. In this way, an emergency call maybe enabled when an emergency call demand is detected. If no emergencycall demand is detected, then the system reverts to power down mode,conserving power.

More details and aspects are mentioned in connection with the examplesdescribed above or below. The example shown in FIG. 5 may comprise oneor more optional additional features corresponding to one or moreaspects mentioned in connection with the proposed concept or one or moreexamples described above (e.g. FIGS. 1-4).

Some examples may relate to a computer-readable storage devicecomprising executable instructions that, in response to execution, causeone or more processors of an apparatus for providing a connection to awide area network for voice calls to perform operations, the operationscomprising receiving a voice call signal from a phone by a phoneconnection circuit; generating voice call data packets by a processorcircuit based on the voice call signal received by the phone connectioncircuit; transmitting voice call data packets by a wide area networkcircuit; and switching off at least one of the processor circuit and thewide area network circuit, if a supply voltage drops below a supplyvoltage threshold.

Some examples relate to emergency power management for supportinglifeline (e.g. US 911) in customer premises equipment CPE.

A proposed system may need very low power in power down situations sothat a small battery may be sufficient. To support lifeline for otherCPEs rechargeable batteries may be required with a capacity of about 30Wh in order to achieve for example reasonable standby time of 24 h and10 minute active ‘911’ emergency call.

The aspects and features mentioned and described together with one ormore of the previously detailed examples and figures, may as well becombined with one or more of the other examples in order to replace alike feature of the other example or in order to additionally introducethe feature to the other example.

In the following, examples pertain to further examples.

Example 1 is an apparatus for providing a connection to a wide areanetwork for voice calls, the apparatus comprising: a wide area networkcircuit configured to transmit voice call data packets; a phoneconnection circuit configured to receive a voice call signal from aphone; a processor circuit configured to generate voice call datapackets based on a voice call signal received by the phone connectioncircuit; and a power management circuit configured to trigger switchingoff at least a part of the apparatus to reach a power down mode of theapparatus, if a supply voltage drops below a supply voltage threshold.

In example 2, the subject matter of example 1 may optionally include thepower management circuit being configured to trigger switching on anemergency part of the apparatus to change to an emergency call mode ofthe apparatus, if an emergency call demand is detected.

In example 3, the subject matter of any of examples 1-2 may optionallyinclude the power management circuit being configured to trigger keepinga non-emergency part of the apparatus switched off in the emergency callmode.

In example 4, the subject matter of any of examples 1-3 may optionallyinclude at least one of a LAN circuit and data bus circuitry, which arepart of the non-emergency part of the apparatus.

In example 5, the subject matter of any of examples 1-4 may optionallyinclude the wide area network circuit being part of the emergency partof the apparatus.

In example 6, the subject matter of any of examples 1-5 may optionallyinclude the phone connection circuit comprising a foreign exchangestation circuit, wherein the foreign exchange station circuit is part ofthe emergency part of the apparatus.

In example 7, the subject matter of any of examples 1-6 may optionallyinclude the power management circuit or the phone connection circuitcomprising a current detection circuit configured to detect theemergency call demand, if a current is higher than a current threshold.

In example 8, the subject matter of any of examples 1-7 may optionallyinclude the processor circuit comprising a network microprocessorimplemented as system on chip.

In example 9, the subject matter of example 8 may optionally include thepower management circuit being configured to trigger the system on chipto enter standby or to switch off completely in the power down mode.

In example 10, the subject matter of any of examples 8-9 may optionallyinclude the power management circuit being configured to triggerswitching on an emergency part of the system on chip in the emergencycall mode, while a non-emergency part of the system on chip is keptswitched off, wherein the emergency part of the system on chip isrequired for enabling an emergency call.

In example 11, the subject matter of any of examples 1-10 may optionallyinclude a battery, wherein the power management circuit is powered bythe battery in the power down mode.

In example 12, the subject matter of example 11 may optionally includethe battery having an energy capacity of less than 3 Wh.

In example 13, the subject matter of any of examples 11-12 mayoptionally include the power management circuit being configured toconnect the battery to the phone connection circuit in the power downmode.

In example 14, the subject matter of any of examples 11-13 mayoptionally include the power management circuit being configured todisconnect the battery from the processor circuit in the power downmode.

In example 15, the subject matter of any of examples 11-14 mayoptionally include the power management circuit being configured toconnect the battery to the processor circuit in the emergency call mode.

In example 16, the subject matter of any of examples 11-15 mayoptionally include the power management circuit being configured todisconnect the battery from the wide area network circuit and theprocessor circuit, if the supply voltage is above the supply voltagethreshold.

In example 17, the subject matter of any of examples 1-16 may optionallyinclude the power management circuit comprising a voltage detectioncircuit configured to detect when the supply voltage drops below thesupply voltage threshold.

Example 18 relates to a power management circuit comprising: at leastone switch; a switch control unit configured to control the at least oneswitch; a battery contact interface for connecting the power managementcircuit to a battery; a phone contact interface for connecting the powermanagement circuit to a phone connection circuit; a processor contactinterface for connecting the power management circuit to a processorcircuit; wherein the switch control unit is configured to control the atleast one switch to connect the processor contact interface to thebattery contact interface if a current through the phone contactinterface increases beyond a current threshold.

In example 19, the subject matter of example 18 may optionally include awide area network contact interface for connecting the power managementcircuit to a wide area network circuit, wherein the switch control unitis configured to control the at least one switch to connect the widearea network contact interface to the battery contact interface if thecurrent through the phone contact interface increases beyond a currentthreshold.

Example 20 relates to a method for providing a connection to a wide areanetwork for voice calls, the method comprising: receiving a voice callsignal from a phone by a phone connection circuit; generating voice calldata packets by a processor circuit based on the voice call signalreceived by the phone connection circuit; transmitting voice call datapackets by a wide area network circuit; and triggering switching off atleast one of the processor circuit and the wide area network circuit, ifa supply voltage drops below a supply voltage threshold.

In example 21, the subject matter of example 20 may optionally includetriggering switching on at least a part of the processor circuit andwide area network circuit to change to an emergency call mode if anemergency call demand is detected.

Example 22 relates to a computer-readable storage device comprisingexecutable instructions that, in response to execution, cause one ormore processors of an apparatus for providing a connection to a widearea network for voice calls to perform operations, the operationscomprising: receiving a voice call signal from a phone by a phoneconnection circuit; generating voice call data packets by a processorcircuit based on the voice call signal received by the phone connectioncircuit; transmitting voice call data packets by a wide area networkcircuit; and switching off at least one of the processor circuit and thewide area network circuit, if a supply voltage drops below a supplyvoltage threshold.

Example 23 is an apparatus for providing a connection to a wide areanetwork for voice calls, the apparatus comprising: means fortransmitting voice call data packets; means for receiving a voice callsignal from a phone; means for generating voice call data packets basedon a voice call signal received by the means for receiving a voice callsignal; and means for power management triggering switching off at leasta part of the apparatus to reach a power down mode of the apparatus, ifa supply voltage drops below a supply voltage threshold.

Examples may further be or relate to a computer program having a programcode for performing one or more of the above methods, when the computerprogram is executed on a computer or processor. Steps, operations orprocesses of various above-described methods may be performed byprogrammed computers or processors. Examples may also cover programstorage devices such as digital data storage media, which are machine,processor or computer readable and encode machine-executable,processor-executable or computer-executable programs of instructions.The instructions perform or cause performing some or all of the acts ofthe above-described methods. The program storage devices may comprise orbe, for instance, digital memories, magnetic storage media such asmagnetic disks and magnetic tapes, hard drives, or optically readabledigital data storage media. Further examples may also cover computers,processors or control units programmed to perform the acts of theabove-described methods or (field) programmable logic arrays ((F)PLAs)or (field) programmable gate arrays ((F)PGAs), programmed to perform theacts of the above-described methods.

The description and drawings merely illustrate the principles of thedisclosure. Furthermore, all examples recited herein are principallyintended expressly to be only for pedagogical purposes to aid the readerin understanding the principles of the disclosure and the conceptscontributed by the inventor(s) to furthering the art. All statementsherein reciting principles, aspects, and examples of the disclosure, aswell as specific examples thereof, are intended to encompass equivalentsthereof.

A functional block denoted as “means for . . . ” performing a certainfunction may refer to a circuit that is configured to perform a certainfunction. Hence, a “means for s.th.” may be implemented as a “meansconfigured to or suited for s.th.”, such as a device or a circuitconfigured to or suited for the respective task.

Functions of various elements shown in the figures, including anyfunctional blocks labeled as “means”, “means for providing a signal”,“means for generating a signal.”, etc., may be implemented in the formof dedicated hardware, such as “a signal provider”, “a signal processingunit”, “a processor”, “a controller”, etc. as well as hardware capableof executing software in association with appropriate software. Whenprovided by a processor, the functions may be provided by a singlededicated processor, by a single shared processor, or by a plurality ofindividual processors, some of which or all of which may be shared.However, the term “processor” or “controller” is by far not limited tohardware exclusively capable of executing software, but may includedigital signal processor (DSP) hardware, network processor, applicationspecific integrated circuit (ASIC), field programmable gate array(FPGA), read only memory (ROM) for storing software, random accessmemory (RAM), and nonvolatile storage. Other hardware, conventionaland/or custom, may also be included.

A block diagram may, for instance, illustrate a high-level circuitdiagram implementing the principles of the disclosure. Similarly, a flowchart, a flow diagram, a state transition diagram, a pseudo code, andthe like may represent various processes, operations or steps, whichmay, for instance, be substantially represented in computer readablemedium and so executed by a computer or processor, whether or not suchcomputer or processor is explicitly shown. Methods disclosed in thespecification or in the claims may be implemented by a device havingmeans for performing each of the respective acts of these methods.

It is to be understood that the disclosure of multiple acts, processes,operations, steps or functions disclosed in the specification or claimsmay not be construed as to be within the specific order, unlessexplicitly or implicitly stated otherwise, for instance for technicalreasons. Therefore, the disclosure of multiple acts or functions willnot limit these to a particular order unless such acts or functions arenot interchangeable for technical reasons. Furthermore, in some examplesa single act, function, process, operation or step may include or may bebroken into multiple sub-acts, -functions, -processes, -operations or-steps, respectively. Such sub acts may be included and part of thedisclosure of this single act unless explicitly excluded.

Furthermore, the following claims are hereby incorporated into thedetailed description, where each claim may stand on its own as aseparate example. While each claim may stand on its own as a separateexample, it is to be noted that—although a dependent claim may refer inthe claims to a specific combination with one or more other claims—otherexamples may also include a combination of the dependent claim with thesubject matter of each other dependent or independent claim. Suchcombinations are explicitly proposed herein unless it is stated that aspecific combination is not intended. Furthermore, it is intended toinclude also features of a claim to any other independent claim even ifthis claim is not directly made dependent to the independent claim.

What is claimed is:
 1. An apparatus for providing a connection to a widearea network for voice calls, the apparatus comprising: a wide areanetwork circuit configured to transmit voice call data packets; a phoneconnection circuit configured to receive a voice call signal from aphone; a processor circuit configured to generate voice call datapackets based on a voice call signal received by the phone connectioncircuit; a power management circuit configured to trigger switching offat least a part of the wide area network circuit and/or issue a commandto the processor circuit to transition the processor circuit to a powerdown mode or a low power mode if a supply voltage supplied from anexternal power source drops below a supply voltage threshold; and abattery, wherein the power management circuit is powered by the batterywhile the supply voltage from the external power source is below thesupply voltage threshold.
 2. The apparatus according to claim 1, whereinthe power management circuit is configured to trigger switching on anemergency part of the apparatus to change to an emergency call mode ofthe apparatus, if an emergency call demand is detected.
 3. The apparatusaccording to claim 2, wherein the power management circuit is configuredto trigger keeping a non-emergency part of the apparatus switched off inthe emergency call mode.
 4. The apparatus according to claim 3, furthercomprising at least one of a LAN circuit and data bus circuitry, whichare part of the non-emergency part of the apparatus.
 5. The apparatusaccording to claim 2, wherein the wide area network circuit is part ofthe emergency part of the apparatus.
 6. The apparatus according to claim2, wherein the phone connection circuit comprises a foreign exchangestation circuit, wherein the foreign exchange station circuit is part ofthe emergency part of the apparatus.
 7. The apparatus according to claim2, wherein the power management circuit or the phone connection circuitcomprise a current detection circuit configured to detect the emergencycall demand, if a current is higher than a current threshold.
 8. Theapparatus according to claim 1, wherein the processor circuit comprisesa network microprocessor implemented as system on chip.
 9. The apparatusaccording to claim 8, wherein the power management circuit is configuredto trigger the system on chip to enter standby or to switch offcompletely in the power down mode.
 10. The apparatus according to claim8, wherein the power management circuit is configured to triggerswitching on an emergency part of the system on chip in the emergencycall mode, while a non-emergency part of the system on chip is keptswitched off, wherein the emergency part of the system on chip isrequired for enabling an emergency call.
 11. The apparatus according toclaim 1, wherein the battery has an energy capacity of less than 3 Wh.12. The apparatus according to claim 1, wherein the power managementcircuit is configured to connect the battery to the phone connectioncircuit in the power down mode.
 13. The apparatus according to claim 1,wherein the power management circuit is configured to disconnect thebattery from the processor circuit in the power down mode.
 14. Theapparatus according to claim 1, wherein the power management circuit isconfigured to connect the battery to the processor circuit in theemergency call mode.
 15. The apparatus according to claim 1, wherein thepower management circuit is configured to disconnect the battery fromthe wide area network circuit and the processor circuit, if the supplyvoltage is above the supply voltage threshold.
 16. The apparatusaccording to claim 1, wherein the power management circuit comprises avoltage detection circuit configured to detect when the supply voltagedrops below the supply voltage threshold.
 17. A method for providing aconnection to a wide area network for voice calls, the methodcomprising: receiving a voice call signal from a phone by a phoneconnection circuit; generating voice call data packets by a processorcircuit based on the voice call signal received by the phone connectioncircuit; transmitting voice call data packets by a wide area networkcircuit; and triggering switching off at least part of the wide areanetwork circuit and/or issuing a command to the processor circuit totransition the processor circuit to a power down mode or a low powermode, if a supply voltage provided from an external power source dropsbelow a supply voltage threshold, wherein the supply voltage is providedfrom a battery while the supply voltage from the external power sourceis below the supply voltage threshold.
 18. The method of claim 17,further comprising triggering switching on at least a part of theprocessor circuit and wide area network circuit to change to anemergency call mode if an emergency call demand is detected.
 19. Acomputer-readable storage device comprising executable instructionsthat, in response to execution, cause one or more processors of anapparatus for providing a connection to a wide area network for voicecalls to perform operations, the operations comprising: receiving avoice call signal from a phone by a phone connection circuit; generatingvoice call data packets by a processor circuit based on the voice callsignal received by the phone connection circuit; transmitting voice calldata packets by a wide area network circuit; and switching off at leastpart of the wide area network circuit and/or issuing a command to theprocessor circuit to transition the processor circuit to a power downmode or a low power mode, if a supply voltage supplied from an externalpower source drops below a supply voltage threshold, wherein the supplyvoltage is provided from a battery while the supply voltage from theexternal power source is below the supply voltage threshold.